Step-by-step explanation:
you know how to multiply two expressions ?
every term of every expression is multiplied with every term of the other expression and the results are added (while considering any specific signs, if course).
(2x² + 3)(2x² - 3) = 2x²×2x² + -3×2x² + 3×2x² + 3×-3 =
4x² - 6x² + 6x² - 9 = 4x² - 9
and that is exactly the right side of the original equation.
so, it is correct.
